The CEO of Canadian marijuana producer Canopy Growth says that marijuana is set to disrupt $500 billion in global markets.

Bruce Linton - whose company recently shipped cannabis from Canada to the United States using a yet-undisclosed "DEA-approved partner," told CNBC's Jim Cramer that the "back-of-the-envelope math" pencils out - between therapeutic cannabinoid treatments to a cultural shift from alcohol and tobacco to recreational pot use.

"And so you add all that together, plus the existing $200 billion illicit market, that pretty quickly gets you up around $500 billion," Linton continued. "It sounds like a 'How could it be?' but just do a bit of the back-of-the-envelope math. It's not crazy."